Wind power generating apparatuses (also referred to as “wind turbine” below) are apparatuses which generate electric power when a rotor head having a wind turbine blade rotates upon receiving wind power and the speed of rotation is increased by a gear box to drive a generator.
The rotor head described above is mounted to an end portion of a nacelle that is installed on a wind turbine tower (referred to as “tower” below) and can yaw. The rotor head is supported so as to be rotatable about a rotation axis in a substantially-horizontal lateral direction.
In a conventional wind power generating apparatus 1 shown in FIG. 5, reference numeral 2 in the drawing denotes a tower, 3 a nacelle, and 4 a rotor head. A wind turbine blade mounted to the rotor head 4 is omitted.
The rotor head 4 of the wind power generating apparatus 1 is configured such that a head cover 42 made of resin covers the periphery of a rotor head body 41 as a mold component. An in-head device such as a hub control panel 20 and a main bearing 10 is installed inside the rotor head body 41. Since the in-head device as described above generates heat during operation of the wind power generating apparatus 1, exhaust heat is generated from the in-head device inside the rotor head 4.
Meanwhile, the above in-head device needs to be protected from moisture or salt according to an installation environment of the wind power generating apparatus 1. Thus, the rotor head body 41 has a sealed structure from outside air, so that the exhaust heat of the in-head device such as the hub control panel 20 tends to be stored in the structure.
For example, stable operation is not ensured for electric control devices such as the hub control panel 20 in a high-temperature atmosphere having a predetermined temperature or more due to an upper limit of temperature conditions set for a constituent electric component or the like. Thus, it is concerned that operation continuation of the wind power generating apparatus 1 is affected. That is, when the hub control panel 20 has a high internal temperature at a predetermined temperature or more, it is difficult for the wind power generating apparatus 1 to continue stable operation.
As a technique for cooling the above internal device of the rotor head, it has been proposed to provide an air inlet opening in a leading end portion of the rotor head, for example (e.g., see Patent Literature 1).